Background: At the first interim analysis of the phase 3 ENGOT-cx11/GOG-3047/KEYNOTE-A18 study, the addition of pembrolizumab to chemoradiotherapy provided a statistically significant and clinically meaningful improvement in progression-free survival in patients with locally advanced cervical cancer. We report the overall survival results from the second interim analysis of this study., Methods: Eligible patients with newly diagnosed, high-risk (FIGO 2014 stage IB2-IIB with node-positive disease or stage III-IVA regardless of nodal status), locally advanced, histologically confirmed, squamous cell carcinoma, adenocarcinoma, or adenosquamous cervical cancer were randomly assigned 1:1 to receive five cycles of pembrolizumab (200 mg) or placebo every 3 weeks with concurrent chemoradiotherapy, followed by 15 cycles of pembrolizumab (400 mg) or placebo every 6 weeks. Pembrolizumab or placebo and cisplatin were administered intravenously. Patients were stratified at randomisation by planned external beam radiotherapy type (intensity-modulated radiotherapy [IMRT] or volumetric-modulated arc therapy [VMAT] vs non-IMRT or non-VMAT), cervical cancer stage at screening (FIGO 2014 stage IB2-IIB node positive vs III-IVA), and planned total radiotherapy (external beam radiotherapy plus brachytherapy) dose (<70 Gy vs ≥70 Gy [equivalent dose of 2 Gy]). Primary endpoints were progression-free survival per RECIST 1.1 by investigator or by histopathological confirmation of suspected disease progression and overall survival defined as the time from randomisation to death due to any cause. Safety was a secondary endpoint., Findings: Between June 9, 2020, and Dec 15, 2022, 1060 patients at 176 sites in 30 countries across Asia, Australia, Europe, North America, and South America were randomly assigned to treatment, with 529 patients in the pembrolizumab-chemoradiotherapy group and 531 patients in the placebo-chemoradiotherapy group. At the protocol-specified second interim analysis (data cutoff Jan 8, 2024), median follow-up was 29·9 months (IQR 23·3-34·3). Median overall survival was not reached in either group; 36-month overall survival was 82·6% (95% CI 78·4-86·1) in the pembrolizumab-chemoradiotherapy group and 74·8% (70·1-78·8) in the placebo-chemoradiotherapy group. The hazard ratio for death was 0·67 (95% CI 0·50-0·90; p=0·0040), meeting the protocol-specified primary objective. 413 (78%) of 528 patients in the pembrolizumab-chemoradiotherapy group and 371 (70%) of 530 in the placebo-chemoradiotherapy group had a grade 3 or higher adverse event, with anaemia, white blood cell count decreased, and neutrophil count decreased being the most common adverse events. Potentially immune-mediated adverse events occurred in 206 (39%) of 528 patients in the pembrolizumab-chemoradiotherapy group and 90 (17%) of 530 patients in the placebo-chemoradiotherapy group. This study is registered with ClinicalTrials.gov, NCT04221945., Interpretation: Pembrolizumab plus chemoradiotherapy significantly improved overall survival in patients with locally advanced cervical cancer These data, together with results from the first interim analysis, support this immuno-chemoradiotherapy strategy as a new standard of care for this population., Funding: Merck Sharp & Dohme, a subsidiary of Merck & Co., Competing Interests: Declaration of interests DL, YX, KH, GS, ML, PR-E, AA, JC, LR, AJPdSG, FCM, LH, HA, J-YL, VS, FZ, LG, JS, ET, KL, NC, C-LC, MB, HZ, AO, MC, EP, TU, SP, and LRD received funding to their institutions from Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA (MSD) to support the study. DL reports grants or contracts from AstraZeneca, Clovis Oncology, Pharma&, Genmab, GSK, Immunogen, MSD, Pharmamar, Novartis, Seagen, Alkermes, Incyte, Roche, and Corcept; consulting fees from AstraZeneca, Corcept, Clovis Oncology, Daiichi Sankyo, Genmab, GSK, Immunogen, MSD, Novartis, Oncoinvest, Novocure, Seagen, and Sutro; speaker fees from AstraZeneca, Corcept, Genmab, GSK, Immunogen, MSD, and Seagen; travel grants from AstraZeneca, Menarini, GSK, and MSD; advisory board participation for AstraZeneca, Corcept, Clovis Oncology, Daiichi Sankyo, Genmab, GSK, Immunogen, MSD, Oncoinvest, Novocure, Seagen, and Sutro; and leadership or fiduciary role in other board, society, committee, or advocacy group, paid or unpaid, for GCIG, MITO, and ENGOT. YX reports study funding, paid to the Peking Union Medical College Hospital, and support for attending meetings or travel from MSD. KH reports research contracts from Daiichi Sankyo, Eisai, MSD, and Takeda; advisory board fees from Chugai, Eisai, Takeda, MSD, Roche, Genmab, Sanofi, GSK, and Zymeworks; honoraria from Daiichi Sankyo, AstraZeneca, Chugai, Eisai, Genmab, MSD, Takeda, Sanofi, Kyowa Kirin, Kaken, and GSK; and travel support from Regeneron and Seagen. GS reports consulting fees from AstraZeneca, MSD, Coviden AG (a Medtronic company), Johnson & Johnson, and TESARO Bio Italy; and payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or education events from Baxter Healthcare, Olympus Europa, Intuitive Surgical, GSK, and Clovis Oncology Italy. ML reports payment for expert testimony from MSD, support for attending meetings or travel from MSD and AstraZeneca; and other financial or non-financial interests from MSD, AstraZeneca, and Roche. PR-E reports honoraria for educational events from MSD, AstraZeneca, Novartis, Asofarma, Pfizer, and Roche; support for attending ESMO and ASCO meetings from AstraZeneca, Pfizer, and Asofarma; and honoraria for advisory boards from MSD, Roche, AstraZeneca, Asofarma, BMS and Novartis. LR reports medical writing support from Merck, institutional grants from Merck, Zentalis, Karyopharn, GOG Foundation, Regeneron, ImmunoGen, Acrivon, CanariaBio, Corcept Therapeutics, and Seagen; consulting fees from AstraZeneca, Merck, GSK, Genmab, Seagen, GOG Foundation, Zentalis, ImmunoGen, Semline, Eisai, Caris, Nykode, and Clovis; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from Seagen and Genmab; and leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid, from GOG Foundation. AJPdSG reports consulting fees and payment for expert testimony from Bayer, Astellas, and Janssen; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events for expert testimony from Astellas, AstraZeneca, Bayer, and Janssen; and participation on a data safety monitoring board or advisory board for Astellas, Bayer, and Janssen. FCM reports honoraria for presentations from MSD and BMS; support for attending meetings or travel from AstraZeneca and MSD; and advisory board participation from Janssen and MSD. J-YL reports support for the present manuscript from MSD; grants or contracts from Advenchen, Ascendis Pharma, Alkermes, AstraZeneca, Beigene, BergenBio, BMS, CanariaBio, Corcept, Cellid, CKD, Clovis Oncology, Eisai, Genmab, Genemedicine, GII, GSK, ImmunoGen, Janssen, Kelun, Merck, Mersana, MSD, Novartis, Onconic Therapeutics, ONO, Regeneron, Roche, Seagen, Sutro, Synthon, and Takeda; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from AstraZeneca, Janssen, MSD, Roche, Takeda, and ONO; and leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid, for AstraZeneca, CanariaBio, Genmab, GII, ImmunoGen, Seagen, Merck, Sutro, Regeneron, and MSD. FZ reports payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events, consulting fees, support for attending meetings or travel, and data safety monitoring board and advisory board participation for AstraZeneca, Daiichi, Eli-Lilly, Merck, Novartis, MSD, Pfizer, Genesis-Pharma, and Roche. LG reports institutional grants from IMV, Pfizer, Sutro Bio, Pharma, Merck Sharpe Dohme, Corcept Therapeutics, ImmunoGen, Shattuck Labs, Roche, Tesaro, K-Group, Beta Inc., GOG Foundation, GSK, AstraZeneca, OncoQuest Pharmaceuticals, Novocure, Alkermes, Espersas, and Mersana; consulting fees from Merck and GSK; payment or honoraria for lectures and presentations from Merck and GSK; support for attending meetings or travel from GSK, Merck, EndomERA, and Zentalis; and participation on advisory board meetings for GSK, Merck, Eisai, Novocure, Kora Health, Corcept, ImmunoGen, Canariabio, and Repare Therapeutics. JS reports grants or contracts from Roche, MSD, GSK, Tesaro, AstraZeneca, Eisai, Merck, and Novocure; consulting fees from Immunogen, Incyte, GSK, AstraZeneca, Clovis, Novocure, MSD, Eisai, and Merck; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from Immunogen, Incyte, GSK, AstraZeneca, Clovis, Novocure, BMS, Eisai, and Novartis; support for attending meetings or travel from GSK, Astra Zeneca, Roche, Novocure, Immunogen, Incyte, MSD, and Eisei; participation on a data safety monitoring board or advisory board for Immunogen, Incyte, GSK, AstraZeneca, Clovis, Novocure, Bristol Myers Squibb, MSD, Merck, Bayer, and PharmaMar; leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid, for ENGAGE, ESGO, ASCO, ESGO, GCIG, Deutsche Stiftung Eierstockkrebs, and AGO; and medical writing assistance from MSD. ET reports honoraria for presentations and meeting travel support from Elektra. KL reports study funding from MSD; grants or contracts from GSK; lecture honoraria from Eisai and AstraZeneca; participation on a data safety monitoring board for Karyopharm; participation on an advisory board for Eisai, MSD, Nykode, AstraZeneca, and GSK; and serving as deputy medical director for the Nordic Society of Gynecological Oncology Clinical Trial Unit. NC reports institutional grants from AstraZeneca and Roche; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from GSK and MSD; payment for participation on a data safety monitoring board or advisory board for AstraZeneca, Clovis Oncology, Eisai, GSK, ImmunoGen, Mersana, MSD, Merck, Nuvation Bio, Onxerna, Pfizer, PharmaMar, Pieris, Roche, and Novocure; and non-remunerated leadership role as Chair of the Alleanza Contro il Tumore Ovarico Scientific Committee. MB reports honoraria for lectures and educational events from Roche, AstraZeneca, and GSK; and support for attending meetings from Roche, AstraZeneca, and Viatris. AO reports consulting fees from Agenus, AstraZeneca, Clovis Oncology, Corcept Therapeutics, Deciphera Pharmaceuticals, Daïichi Sankyo, Debiopharm International, Eisai, Exelisis, F. Hoffmann-La Roche, Genmab, GSK, ImmunoGen, Itheos, MSD, Mersana Therapeutics, Myriad Genetics, Novocure, OncoXerna Therapeutics, PharmaMar, Regeneron, Sattucklabs, Seagen–Pfizer, Sutro Biopharma, TORL Therapuetics, Zentalis, and Zymeworks; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from NSGO, Peerview, Peervoice, Medscape, Asociación Colombiada de Ginecológos Oncólogos, ESO, AstraZeneca, and GSK; support for attending meetings or travel from AstraZeneca, PharmaMar, and Roche; participation on a data safety monitoring board or advisory board from Agenus, AstraZeneca, Clovis Oncology, Corcept Therapeutics, Deciphera Pharmaceuticals, Daïichi Sankyo, Debiopharm International, Eisai, Exelisis, F Hoffmann-La Roche, Genmab, GSK, ImmunoGen, Itheos, MSD, Mersana Therapeutics, Myriad Genetics, Novocure, OncoXerna Therapeutics, PharmaMar, Regeneron, Sattucklabs, Seagen–Pfizer, Sutro Biopharma, TORL Therapuetics, Zentalis, and Zymeworks; leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid, for Gynecologic Cancer Intergroup and European Society for Medical Oncology; and other financial or non-financial interests in Gynecologic Cancer Intergroup, European Society for Medical Oncology, American Society of Clinical Oncology, Spanish Society of Medical Oncology, and GOG Foundation. EP reports provision of study material from MSD; honoraria for lectures, presentations, and educational events from MSD, Roche, GSK, and AstraZeneca; and receipt of investigational drug for study treatment from MSD. PL, KY, ST, and SMK are current or former full-time employees of MSD and hold stock or restricted stock units in the company. SP reports research funding from Roche, MSD, GSK, Pfizer, and AstraZeneca; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from AstraZeneca, MSD, Roche, Pfizer, Novartis, and GSK; and participation on a Data Safety Monitoring Board or Advisory Board for GSK, MSD, Eisai, Biontech, and AstraZeneca. LRD reports institutional grants from Merck, Genentech, Roche, AbbVie, Acrivon, Advaxis, Aduro BioTech, Alkermes, Blueprint, Constellation, Eisai, GSK, Novartis, Immunogen, Inovio, Iovance, Karyopharm, KSQ Therapeutics, Lycera, Morab, MorphoTek, Naveris, Nurix, OncoQuest, Pfizer, Syndax, Tesaro, and Zentalis; royalties or licenses from UpToDate, Wiley, and ASCO; editing for ASCO Connection; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from Advance Medical, CEA Group, and Clinical Care Options; participation on a data safety monitoring board for Innovia and Aegenus (payment to institution); and roles as Secretary Treasurer for SGO (unpaid) and on the Editorial Board of the British Journal of Obstetrics and Gynaecology., (Copyright © 2024 Elsevier Ltd. All rights reserved, including those for text and data mining, AI training, and similar technologies.)